The Yanbian Korean Autonomous Prefecture is an autonomous prefecture of eastern Jilin province in Northeast China, bordered to the north by Heilongjiang province, to the west by Jilin's Baishan and Jilin City, to the south by North Korea's North Hamgyong Province, and to the east by Russia's Primorsky Krai. Yanbian is known as the region with the largest number of ethnic Koreans (Chaoxianzu) living in China. It is sometimes referred to as the "Third Korea".
The prefectural capital is Yanji and the total area is 42,700 square kilometres (16,500 sq mi). The prefecture has an important Balhae archaeological site – the Ancient Tombs at Longtou Mountain – which includes the Mausoleum of Princess Jeonghyo.